Radio tuning mechanism



Aug. 21, 1928.

G. R. FREMONT RADIO TUNING MECHANISM Filed Aug. 18, 1925 s ShetsSheet 1 Aug. 21, 192& l",68l,529

G. R. FREMONT RADIO TUNING MECHANISM Filed Au 18, 1925 3 Sheets-Sheet 3 Patented Aug. 21, 1928.

UNITED STATES PATENT oFFIcE.

GEORGE IR. FREMONT, OF RICHMOND, VIRGINIA.

Application filed August 18, 1925. Serial No. 51,275.

My invention is a radio tuning mechanism, and its principal object is to provide a radio tuning mechanism wherein the various adjustable tuning elements of a radio outfit 6 may be simultaneously adjusted through the instrun'ientality of a common control arranged at a point remote from the radio cabinet.

A further object of the invention is to pro- H vide a radio tuning mechanism adapted to be manually set for tuning in a predetermined station, whereby to operate an electrically controlled mechanism which will adjust or tune in the condensers in synchrofi nism, and after the completion'of such adjustment will be automatically rendered inoperative.

Another object of the invention is to provide a remote control mechanism for radio receiving sets which will permit a maximum number of radio stations to be logged, thus permitting exceedingly close or fine tunmg.

It is another object of my invention to provide a radio call letter or tuning chart,

-'" wherein the call letters representing the sta: tions are arranged in groups, each group having a key thus enabling the operator to quickly tune in.

Still another object of the invention is to I provide a radio tuner which will permit the operator to be seated among the audience, and thereby be relieved of the noise and other annoyance and discomfort incident to operating the present radio control dial.

Further, the invention contemplates means for controlling or tuning a radio set embodying a portable control unit containing a scale or log of the various radio stations, together with electrical means associated with the condensers or tuning elements which are operated by the portable control unit.

Briefly stated, the invention consists of two motor circuits, one of which is located in the radio cabinet and geared to the axially adjustable condensers or tuning elements, and the other being located in a portable container adapted to repose upon the lap of the operator at a point remote from the radio cabinet, and switch means for simultaneously operating the motors to tune the condensers or tuning elements to a predetermined wave length or station.

On the drawings, Figure 1 is a diagrammatical view of the invention. 1

Figure 2 is a view of a radio having one of the side walls of its cabinet removed, and showing parts of the invention associated with the receiving set. T

Figure 3 is an enlarged plan view of the control unit embodied in the invention.

Figure 4 is a view partly in elevation and partly in perspective of the radio receiving set and the remote control unit.

Figpre 5 is a detail View partly in section and partly in elevation of the remote control unit, and

Figure 6 is a modified embodiment of the invention.

Referring to the drawings in detail, wherein corresponding characters of reference denote corresponding parts throughout the several views, thenumeral 5 designates a conventional radio receiving outfit, and which includes the cabinet 6, loud speaker or horn 7 and vertically alined rotatable condensers or tuning elements 7, 8 and 9, all of which are mounted upon shelves 10. Each of the condensers or tuning elements includes a shaft 11, and fixed tothe shaft 11 of the condenser or tuning coil 7 is a plurality of pulleys 12. A single pulley 13 is fixed to each of the other shafts 11 of the condensers or tuning elements 8 or 9. A pulley 1 1 is revoluble about the upper end of the horn or loud speaker 7' and is in vertical alinement with one of the pulleys 12. A drive belt 15 is engaged with-the last mentioned pulley 12 and belt 14. Similar drive belts are engaged about the remaining pulleys 12 and 13, respectively.

Also fixed to the shaft 11 of the condenser or tuning element 7 is a worm wheel 16 that is engaged by a horizontal worm shaft 17.

Right and left drive motors 18 are supported by means of brackets 19 at the opposite 'ends of the worm 17. These brackets 19 are formed'with forwardly projecting threaded shanks 19', each of which extends through a vertically disposed slot 19* formed in the front wall of the cabinet. Wingnuts 19 are threaded on these shanks and serve to hold the brackets in a position where the worm ,17 normally engages the worm wheel 16, or in a lowered position where this worm 17 will not engage the worm wheel when it is desired to manually adjust the tunin Y elements as will be hereinafter describe The shafts of these motors are fixed to the ends of the worm shaft 17 by means of fiber or other non-conducting coupling elements 20.

A log or dial 21 of the'v'arious radio call stations is provided on the front wall of the cabinet 6 and encircles the flared end of the loud speaker or horn 7 A circular slot 22 is also'provided in this front wall of the cabinet 6 and is disposed at the inner edge of the log'or dial 21. An arm 23 is fixed to revolve with the pulley 14 and projects outwardlythrough the slot 22 and carrles a pointer or finger 24,whioh is movable over the dial 21.

A portable control mechanism is provided which comprises a relatively flat rectangular casing 25 adapted to be supported upon the lap of the operator at a point remote from the cabinet 6. A worm wheel 27 is journaled within this casing and is driven by right and left drive motors 28 and 29, respectively, also contained in the casing 25. A worm shaft 30, identical to the worm shaft 17, en-

gages this worm wheel 27 and is connected with the motors by fiber or other non-conducting couplings 31.

The numeral 32'designates asource of electric energy which ma be mounted in the cabinet 6 or any other esirable place. Leading from the source of electric energy 32 is a pair of main feed and return conductors 33 and 34 respectively, and a pair of motor circuits which comprise pairs of conductors 35 and 36 respectively. A pair of electrically connected rheostats 37 and 38 are mounted upon the upper face of the casin 25. One

end of the rheostat 37 is electncally connected to the main feed conductor-33, while the movable switch arm of this rheostat 37 is electrically connected to the return conductor 34, and one of the conductors 36 by means of a branch wire 40. The other rheostat 38 is electrically connected with one of the conductors 35. An electromagnet 41.is

arranged within the -casing 25, and includes an I-shaped pivoted armature 42. v This ar-. mature 42 acts as a circuit maker and breaker to the motors, and normally engages spaced contacts connected with one of the conductors 35 and 36 respectively. The pivoted switch arm of the rheostat 38 is electrically connected with one ofthe conductors 35 by way of a branch wire 39; It

' will be seen that this circuit connects the two right drive motors and the two left drive motors in independent seriescircuits which are controlled by the switch arms of the rheostats 37 and 38.

Secured to the upper face of the casing 25 is a pair of concentrically arranged semicircular yieldable elements 43, having the-inner edges of their under faces cut away as at 44 and adapted to frictionally engage the outer ends of sets of sli s 45 which are arranged in edge to edge re ation as shown. These slips 45 contain the symbols or call letters of radio broadcasting stations. Ar-

ranged concentric to the semi-circular velements 43 and disposed at" the inner ends of the sli s 45 are semi-circular clam s 46, the latter ing resiliently hinged to t e casin 25 as at 46', and thereby normallyurged into clamping engagement with the inner ends of these slips. An elastic tube 47 is carried by each of the clamps to revent mutilation or marring of the slips by these clamps. An operating handle 48 is carried by each tube 47 at a point centrally of its ends, whereby to swing the clamps awayfrom the casing when it is desired to remove or apply the slips. These slips 45 are arranged in groups, and each group being arby thecasin 25. It will therefore be manifest that if t e operator desires to tune in on a particular station, for example, Station W-E-A-F, it is'only necessary to look to group'B .and find Station 5 of such group, the groups beingconsecutively numbered on the tubes 47 as indicated at 49". It will ranged coincident to a key-letter 48 carried be observed that this arrangement-provides 1 a logechart which will permit a maximum nun'i r of broadcasting stations to be logged. The same istrue of the log chart .or dial 21 carried by the cabinet 6, and which is identical in construction.

A series of plug receiving openings 46 is provided in an arcuate conductor strip 45' secured to the under face of the top wall of the casing 25, and, located at the outer edge of the outermost semi-circular ret'aining element 43; Each of these plug receiving openings 46" is in alinement with one of the sli s 45. Similar openings 43 are provided in the top wall of the casing and register with the openings 46". v

Fixed to the axis of the worm gear is adapted to traverse the openings 46 upon the rotation of the-worm gear 27. A broad- 27 a a hand 47 that is insulated as at 48 and casting station selecting hand 48' is pivoted I to the axis of the worm gear 27 and is manually' movable over the slips 45 and adapted to register with any one of-the openings 43' corresponding to a selected station. A plug 49' is arranged in the openings of the se- 1 one end arranged in the path of movement of shown in Figure 1 this armature 2 is pivoted intermediate-its ends, and the electromagnet 53 is arranged below the outer end of this armature, so that upon energization of the magnet the forward end of the armature will be swung upwardly to engage one end of the brake element 51 to move and hold the latter into braking engagement with the worm gear 16. Branch wires 54 lead from the electro-magnet 53 to the conductors 49 and 51 respectively.

In addition to attaining proper tuning of the tuning elements, I also provide means for controlling the sound volume. This means comprises a disk 60 carried by the shaft 61 of the volume control element. An electric motor 62 is connected with the conductors 33 and 34 by lead wires 63. A friction drive element 64 is arried by the motor shaft and frictionally contacts with the disk 60 to rotate the latter to any desired position. The motor 62 is controlled by a rheostat switch 65 carried by the casing 25, and is connected with the conductors 33 and 34 by lead wires If it is desired to adjust the tuning elements manually, this may be accomplished by means of a hand operated shaft 53 journaled in the cabinet 5 and projecting laterally from one side thereof as shown in Figure 4. A; friction drive element 54 is carried by this shaft 53 'and engages one face of the worm wheel 16 as illustrated in Figure 2. However,- before adjusting this shaft 53 the worm 17 is first disengaged from the worm gear 1'6 by lowering the adjustable brackets'19.

In Figure 6, a modification of the invention is illustrated. This embodiment of the invention contemplates an attachment for a single tuning or condensing element,.and comprises a casin 55. which 1s supported on vertically adjusta le legs 56. The rear wall of this casing 55 is provided with a central opening 57 through which the shaft 58 of the tuning or condensing element asses. In this instance the worm gear 16 1s fixed directly to the shaft 58. The -motor driving connections and remote control are identical to the structure above described.

As illustrated in Figure 4, all of the con-' ductors which extend from the cabinet 6 to the portable control mechanism are encased in a cable or sheathing 67.

In the operation of the invention, the operator moves the hand 48 to a selected pair of openings 43 and 46 in which the plug 49 has been previously placed. Either the right or left drive motors are set in operation by manipulating the corresponding switch arm to drive the .worm gears 16 an 27 in synchronism, until the hand 47 engages the plug 49' to complete an electric circuit through the magnet 41, the latter attracting its armature 42 swings it to the full hne position indicated in Figure 1 breaking the circuit to the motors. At the same time the electro-magnetv 53 is energized and actuates the brake element 51 to stop the worm gear 16 asabove stated. During the rotation of the worm gear 16 the tuning elements or condensers will be adjusted or oscillated through the medium of the driving connections above stated. It will be thus observed that the tuning elements orcondensers will be simultaneously set, where they will tune in on the selected broadcasting station.

While I have illustrated and described one embodiment of the invention, I wish to emphasize that I do not limit my self to the exact construction set forth, but that I may make alterations and inodifications therein, and such alterations and modifications are only governed by the appended claims.

'l/Vhat I claim is 1. The combination with a radio receiving set, of means operatively connecting all of the tuning elements thereof, drive means for simultaneuosly rotating the tuning ele'- ments including a motor driven element, a portable casing, a log chart carried thereby,

.a motor driven rotatable element in the casing, electrical means connecting the motors for operating the same in synchronism, means carried by the portable casing for selecting any one of a plurality of radio stations whose call letters are'located in the logchart, and means operated by the rotatable element in the portable casing to render the motors inoperative when the tuning elements have reached a point where they will tune in on the selected ing station.

2. The combination with a radio re"eiving set, of means for simultaneuosly adjusting the tuning elements thereof, which includes a motoractuated movable member operatively connected with the tuning elements, a

portable unit, a motor actuated movable member which moves in synchronism with the first mentioned movable member, selective means associated with .the unit for selecting a predetermined radio broadcast ing station, and means actuated by the station broadcasting selecting means whereby to render the motors inoperative when the tuning elements tune in onthe selected station.

3. The combination with a radio receiving set including a plurality of rotatable tuning elements, operative connections between all of such tuning elements, a common electrical drive means for simultaneously adjusting the tuning elements about their axes a portable chart containing indicia arranged at predetermined positions on the chart and representing radio broadcasting stations, a motor driven element carried by the chart, hands movable over the chart and normally broadcast insulated from each other, and one of which being fixed to rotate with such motor driven element, and the other being adapted to be manually set to register with a desired station call symbol, a pivoted brake element supported adjacent the electrical drive means, an electric circuit, an electro-ma et therein and arranged adjacent the bra e element adapted to be energized to engage the brake element with the electricalv drive means to render the latter inoperative when the two hands coincide.

4. The combination with a radio receiving set including a plurality of rotatable tuning elements, means operatively connecting the tuning elements together, a driven element fixed to one of the tuning elements, right and left electric motors geared to the driven element, a portable casing, a driven element journaled therein, right and left motors in the casing and geared to such driven element, independent electric circuits connecting the right and left drive motors, a chart on the casing containing the various radio broadcasting station symbols, switches for controlling each of the circuits, means for selecting any one of the broadcasting station symbols and-operable to render the motors inoperative after the driven elements have moved a predetermined distance.

5. Means for controlling the tuning elements of a radio receiving set comprising a driven element, means operatively connecting all the tuning elements and drive elements together, sets of right and left drive motors, electric circuits connecting the right and left drive motors of each set in series, a conductor strip having a series of pin receiving openings, each of which corresponds to the wave length of a predetermined radio broadcasting station, a brake mounted adjacent the drive element, normally inoperative electrical means for moving the brake element into engagement with the drive element, a contact pin engageable in any one of the openings, and a pair of pivoted norsuch motors, whereby to operate the electrical brake actuating means to stop the drive element when the tuning elements occupy a position where it willtune in on a selected station..

6. A remote control attachment for radio' tuning elements comprising a motor operated drive element to be fixed upon the shaft of such elements, a portable control unit in cluding 'a motor" driven rotatable element, electric circuits connecting such motors to operate in unison, switches controlling the circuits',-electrically operated brake element adapted to engage the first mentioned drive element when the last mentioned drive element has rotated a predetermined distance.

7 The combination with a radio receiving set including a plurality of rotatable tuning elements, means operatively connecting the tuning elements together, a driven element fixed to one of the tuning elements, right and left electric motors geared to the driven element, a portable casing,a driven element journaled therein, right and left motors in the casing and geared to such driven element, inde endent electric circuits connect-- ing the rig t and left drive motors, a chart on the casing containing the various radio broadcasting station symbols, switches for.

controlling each of the circuits, means for selecting any one of the broadcasting station symbols and o erable to render the motors inoperative a er the driven elements have moved a predetermined distance, a graduated dial on the radio cabinet, an arm movable over the dial and fixed to rotate with part of the tuning element rotating means, and serving as a close-up tuning element adjusting member.

In testimony whereof Iaflix my signature.

GEO. R. FREMONT. 

